1 package org.e2etrace.timer;
2
3 /*
4 * Copyright 2006 Gunther Popp
5 *
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 /**
20 * Utility class to determine the e2etrace timer configuration and accuracy.
21 * <p>
22 *
23 * The source code of this utility class is based on the article "My kingdom for
24 * a good timer!" by Vladimir Roubtsov on JavaWorld (see link below).
25 *
26 * @author Gunther Popp
27 * @see <a
28 * href="http://www.javaworld.com/javaworld/javaqa/2003-01/01-qa-0110-timing.html">Article
29 * "My kingdom for a good timer!"</a>
30 *
31 */
32 public class PrintTimerAccuracy {
33
34 /**
35 * Main method.
36 *
37 * @param args command line args
38 */
39 public static void main(String[] args) {
40 ITimerFactory tf = new DefaultTimerFactory();
41 ITimer timer = tf.newInstance();
42 long time, time_prev;
43
44 System.out.println("e2etrace - PrintTimerAccuracy\n");
45 System.out.println("Used timer type: " + timer.getClass().getName() + "\n");
46
47 // JIT/hotspot warmup:
48 timer.start();
49 for (int r = 0; r < 3000; ++r) {
50 timer.measure();
51 }
52
53 timer.start();
54
55 for (int i = 0; i < 5; ++i) {
56 time = timer.measure();
57 time_prev = time;
58 while (time == time_prev)
59 time = timer.measure();
60
61 System.out.println("accuracy = " + (time - time_prev) + " ms");
62 }
63 }
64 }